Fact · Voice privacy and security
For custom speech and custom voice, Microsoft says your uploaded data is stored in Microsoft's storage by default, unless you prepare your own storage account.
Checked against its source on October 17, 2026
In the source's own words
“By default, your data is stored in Microsoft's storage and your Speech resource uses Microsoft-managed encryption keys.”
Speech service encryption of data at rest, Microsoft, Microsoft Learn, 2026, Custom speech and custom voice, storage.
Open the original- What it measures
- The sentence follows Microsoft's list of what custom speech and custom voice may store in the cloud, which includes speech trace data and uploaded training and test data. It applies to those custom features, not to standard real-time transcription.
- What it does not show
- The page offers your own storage account as an option, and says that Speech service cannot access your own storage directly. It does not give a retention period for uploaded training data.